Portal vein recanalization and transjugular intrahepatic portosystemic shunt in chronic portal vein thrombosis: a narrative review

Portal vein thrombosis (PVT) is a heterogeneous and clinically significant complication of liver cirrhosis, primary hepatobiliary malignancy, and various systemic prothrombotic states. It is associated with advanced portal hypertension, increased surgical complexity during liver transplantation, and higher mortality. The aim of this manuscript is to provide a narrative review of PVT and portal vein recanalization combined with transjugular intrahepatic portosystemic shunt (PVR-TIPS), detailing epidemiology, pathophysiology, and diagnostic classifications while exploring evolving medical and interventional management strategies. A comprehensive narrative review of the existing literature was conducted, incorporating clinical practice guidelines from major societies (AASLD, Baveno VII, EASL, and AGA) and recent prospective and retrospective studies regarding the management of non-malignant PVT in both cirrhotic and non-cirrhotic patients. PVT occurs in approximately 1% of the general population but affects up to 44% of candidates for liver transplantation (LT). Its development is governed by Virchow's triad, with reduced portal flow velocity (<15 cm/s) being the primary independent predictor in cirrhosis. Diagnosis relies on Doppler ultrasound as a first-line screening tool, followed by contrast-enhanced computed tomography or magnetic resonance imaging to define the degree of occlusion, extent, and chronicity using standardized nomenclature. Medical management with anticoagulation is the cornerstone for recent PVT (<6 months), achieving recanalization in 40%–75% of cases. For chronic obliterative PVT or refractory complications (variceal bleeding or refractory ascites), PVR-TIPS has emerged as a safe and highly successful intervention, with technical success rates ranging from 75% to 100% in expert centers. PVR-TIPS facilitates physiologic end-to-end portal anastomosis during LT in up to 96%–100% of cases, significantly improving transplant feasibility and outcomes. The management of PVT has transitioned toward highly individualized strategies. Standardized classification remains essential for guiding therapy. While medical management is effective for recent-onset disease, PVR-TIPS represents a transformative interventional advancement for chronic obliterative PVT, restoring physiologic flow and optimizing candidates for curative liver transplantation.

Portal vein thrombosis (PVT) is the obstruction of the portal venous system by a blood clot, occurring in patients with or without underlying liver disease (1, 2). While relatively rare in the general population, its prevalence rises sharply with the severity of cirrhosis, affecting up to 44% of candidates for liver transplantation (LT) (1, 3, 4).

The development of PVT is driven by the components of Virchow's triad: reduced portal blood flow (stasis), a hypercoagulable state, and vascular endothelial injury (1, 3, 5). These mechanisms are triggered by a variety of systemic risk factors, such as myeloproliferative neoplasms (MPN) and inherited thrombophilias, and also local factors, including intraabdominal inflammation, malignancy, and surgical trauma (1, 2, 4, 6).

Prompt diagnosis relies on Doppler ultrasound as the first-line tool, followed by contrast-enhanced cross-sectional imaging to map the anatomical extent and distinguish bland from malignant forms (2, 4, 7, 8). Anatomical grading, such as the Yerdel classification, and standardized nomenclature based on chronicity are essential for guiding therapeutic decisions (4, 7, 9, 10).

Management strategies continue to evolve, balancing the goals of portal system recanalization with bleeding risks (9, 11). While anticoagulation (AC) remains the cornerstone for recent-onset PVT, advanced endovascular interventions—particularly portal vein recanalization combined with transjugular intrahepatic portosystemic shunt (PVR-TIPS)—have emerged as effective treatments for chronic obliterative disease to manage portal hypertension and optimize transplant candidacy (6, 8, 10–12).

The aim of this manuscript is to provide a narrative review of portal vein (PV) thrombosis and PVR-TIPS, exploring epidemiology, pathophysiology, and diagnostic classifications, while detailing the technical evolution and clinical outcomes of endovascular interventions designed to manage portal hypertension and restore physiologic portal flow to optimize the candidacy of patients awaiting liver transplantation.

Epidemiology of PVT

The epidemiology of PVT varies significantly depending on the presence of underlying liver disease. In the general population, the lifetime risk of PVT is approximately 1%, with autopsy studies reporting prevalence between 0.05% and 1% (1–3, 6). Standardized incidence rates in the general population are estimated between 0.7 and 3.8 per 100,000 inhabitants per year (2, 6, 9).

In patients with cirrhosis, PVT is a frequent complication, with an annual incidence of 3%–17% (3, 11). The prevalence increases with the severity of liver disease; it is reported at less than 1% in compensated cirrhosis, rising to 8%–25% in patients awaiting liver transplantation, and reaching up to 36%–44% in explanted livers (1–3, 7). In cirrhotic patients with hepatocellular carcinoma (HCC), the frequency of PVT can be as high as 35% (1, 7, 12). In non-cirrhotic patients with portal hypertension, the incidence of PVT is estimated at 5%–10% in developed nations and up to 33% in developing countries (2). PVT is generally more common in men, with a median age at diagnosis of approximately 55 years (4, 9).

Pathophysiology

The pathophysiology of PVT is multifactorial and traditionally framed by Virchow’s triad: reduced portal blood flow (stasis), a hypercoagulable state, and vascular endothelial injury (1–3, 5, 6, 9, 12, 13). Reduced Portal Flow (Stasis): In cirrhosis, architectural distortion and increased intrahepatic vascular resistance lead to sluggish portal blood flow (1, 7, 12). A portal flow velocity of less than 15 cm/s is a strong independent predictor for the development of de novo PVT (1, 3, 4, 7, 10). The “NO paradox” in cirrhosis—decreased nitric oxide in the liver but increased availability in splanchnic vessels—further contributes to splanchnic venous dilatation and stasis (12).

Hypercoagulability: Cirrhosis is no longer viewed as a purely hypocoagulable state; rather, it involves a rebalanced hemostatic system prone to hypercoagulability due to increased levels of Factor VIII and von Willebrand factor coupled with reduced levels of natural anticoagulants like Protein C and S (1, 3, 7, 9).

Endothelial Injury and Inflammation: Local endothelial damage can result from abdominal surgery (especially splenectomy), trauma, or inflammatory processes (1, 2, 7, 12). Portal endotoxemia, caused by bacterial translocation from the gut, can trigger the coagulation cascade in the portal vein (3, 5, 7).

Sinusoidal Ischemia: The concept of “parenchymal extinction” suggests that portal venous microthrombi lead to localized ischemia, contributing to liver fibrosis, organ atrophy, and the progression of portal hypertension (9, 14).

Causes and risk factors

Etiological factors are categorized into systemic prothrombotic conditions and local predisposing factors. An underlying cause can be identified in up to 80% of cases with rigorous evaluation, and multiple concurrent factors are present in approximately 15% of patients (1, 6).

Systemic risk factors

Myeloproliferative Neoplasms: These are common systemic causes, identified in approximately 30.5%–32% of non-cirrhotic patients (1, 6). The JAK2 V617F mutation is a major diagnostic criterion for MPN and is found in 17%–35% of PVT cases (1, 2, 9).

Inherited Thrombophilia: Key factors include the Factor V Leiden mutation (3%–9%), the Prothrombin G20210A mutation (14%–15%), and deficiencies in Antithrombin III, Protein C, or Protein S (1, 2, 6, 9, 13).

Acquired Thrombophilic States: These include antiphospholipid syndrome (8%–15%), paroxysmal nocturnal hemoglobinuria, and hyperhomocysteinemia (1, 2, 6, 9).

Hormonal and Life States: Pregnancy, the use of oral contraceptives, and hormonal replacement therapy are established risks (1, 2, 4, 6, 13).

Metabolic Factors: Obesity, diabetes, and metabolic dysfunction-associated steatotic liver disease (MASLD/NASH) are increasingly recognized as independent risk factors (4, 6–10).

Infections: Cytomegalovirus infection and SARS-CoV-2 (COVID-19) have recently been emphasized as triggers for acute PVT (2, 4, 6, 13).

Local risk factors

Local factors are identified in 20%–40% of cases (1, 6, 9). Malignancy: This refers to direct vascular invasion or compression by HCC, cholangiocarcinoma, or pancreatic cancer (1, 2, 7, 12, 13).

Abdominal inflammation: This involves acute pancreatitis (the most common local factor), cholecystitis, appendicitis, diverticulitis, inflammatory bowel disease, and liver abscesses (1, 2, 9, 10, 12, 13).

Surgery and trauma: Splenectomy (particularly laparoscopic), bariatric surgery, colectomy, and abdominal trauma are significant contributors (1, 4, 6, 7, 9, 12, 13).

Pediatric factors: In children, PVT is frequently linked to omphalitis, neonatal umbilical sepsis, and umbilical vein cannulation (1, 4, 7).

Specific risk factors in cirrhosis

Beyond disease severity (Child–Pugh class), MASLD (metabolic dysfunction-associated steatotic liver disease) and metabolic syndrome (obesity, diabetes) are increasingly recognized as independent risk factors for PVT (2, 4, 8). The use of non-selective beta-blockers is a subject of debate; some studies suggest a fivefold increase in PVT risk due to further reduction in portal blood flow, although this may also reflect the underlying severity of portal hypertension (3, 7, 10). Conversely, statins may exert a protective effect by improving endothelial function (3).

Diagnosis

The diagnosis of PVT relies primarily on imaging, as clinical presentations are often non-specific or the condition is discovered incidentally (2, 12). The diagnostic workup aims to confirm the presence of thrombus, define its extent and chronicity, and distinguish benign (bland) from malignant (tumoral) forms (4, 9, 12).

Yerdel classification

The most widely utilized anatomical grading system for PVT, particularly in the context of liver transplantation, is the Yerdel classification (Figure 1) (8, 9). This system categorizes PVT based on the degree of occlusion and anatomical extension into the mesenteric system, thereby guiding surgical planning (3, 10, 15): Grade 1: This is defined as minimal or partial thrombosis of the PV trunk, occupying less than 50% of the vessel lumen (7, 8, 10).

Grade 2: This denotes thrombus occupying more than 50% of the PV trunk, including complete occlusion, with or without minimal extension into the superior mesenteric vein (SMV) (7, 8).

Grade 3: This is characterized by complete thrombosis of the PV trunk and proximal SMV, with the distal SMV remaining patent (7, 8, 10).

Grade 4: This is defined by complete thrombosis of the PV trunk and both the proximal and distal SMV (7, 8, 10).

Standardized nomenclature (AASLD/Baveno VII)

Recent guidelines from the AASLD and Baveno VII have proposed a standardized nomenclature to replace the varied terminology used in clinical practice (4, 10, 12). This system characterizes PVT based on four pillars: Chronicity: Recent PVT is presumed to be present for less than 6 months; chronic PVT is present for 6 months or longer and is typically associated with a portal cavernoma (4, 8, 10, 14).

Degree of occlusion: This is categorized as minimally occlusive (<50%), partially occlusive (>50%), or completely occlusive (no persistent lumen) (4, 6, 10, 14).

Site and extent: This specifically documents involvement of the intrahepatic branches, the main portal trunk, and upstream tributaries such as the splenic or mesenteric veins (2, 4, 12).

Interval change: Thrombus evolution is defined as progressive, stable, or regressive (improvement or complete resolution) based on serial imaging (4, 8, 10, 14).

Imaging modalities

Doppler Ultrasound: This is the first-line screening tool (2–4). Recent thrombi appear as hypo- or isoechoic material within a potentially dilated vein, whereas chronic thrombi are often hyperechoic due to fibrosis or calcification (2, 3, 9, 12). The detection of multiple small serpentine vessels at the porta hepatis is diagnostic of cavernous transformation (9, 12, 16).

Computed Tomography (CT): Multiphase contrast-enhanced CT is essential for mapping the anatomical extent of the thrombus and identifying complications such as bowel wall thickening or pneumatosis, suggestive of intestinal ischemia (1, 2, 4, 9). On non-contrast CT, a fresh thrombus may appear hyperdense (2, 9, 12).

Magnetic Resonance Imaging (MRI): MRI offers high sensitivity (up to 100%) and is particularly useful for detecting biliary complications (portal biliopathy) and differentiating benign from malignant thrombi without radiation exposure (1, 4, 6, 9, 13).

Laboratories

Laboratory tests are generally non-diagnostic for PVT itself (2). In acute cases, there may be a non-specific rise in inflammatory markers (2). While D-dimer levels are frequently elevated in acute PVT, they lack specificity and are not recommended as a primary diagnostic tool (2, 11). A liver function workup is necessary to determine the presence of underlying cirrhosis, which significantly alters the prognosis and management strategy (4, 6, 9). In non-cirrhotic patients, extensive screening for prothrombotic disorders (e.g., MPNs, JAK2 mutations, factor V Leiden) is mandatory (1, 12–14).

Treatment and follow-up

The management of PVT is increasingly tailored to the individual patient, balancing the objective of portal system recanalization against the risk of treatment-related complications, primarily bleeding (1, 7, 17). Goals of Therapy: Treatment goals are dictated by the chronicity of the thrombus and the presence of liver disease: Recent PVT: In both cirrhotic and non-cirrhotic patients, the primary aims are to prevent mesenteric ischemia and infarction, limit thrombus extension, and achieve recanalization to prevent established portal hypertension (4, 6, 11).

Chronic PVT: Management focuses on treating the sequelae of portal hypertension (e.g., variceal bleeding, refractory ascites) and, for cirrhotic patients, optimizing candidacy for LT (8, 12).

Medical Management: AC: Anticoagulation remains the cornerstone of therapy for recent-onset thrombosis (3, 9): Patient Selection: AC is strongly recommended for patients with recent symptomatic PVT, occlusive PVT (>50% obstruction), or potential LT candidates regardless of the degree of occlusion to maintain physiologic portal inflow (3, 4, 11, 14). Conversely, a “wait-and-see” approach with serial imaging every 3 months is often appropriate for asymptomatic, minimally occlusive (<50%) intrahepatic sub-branch thrombi, as spontaneous recanalization occurs in up to 40% of cases (3, 10, 11, 17).

Agents: Initial therapy typically utilizes low-molecular-weight heparin or unfractionated heparin (in select cases) (7, 11, 14). Long-term maintenance often involves vitamin K antagonists or direct oral anticoagulants (DOACs) (3, 11, 14). DOACs are increasingly preferred for patients with Child–Pugh A or B cirrhosis due to their safety profile and lack of monitoring requirements (11).

Duration and Success: AC is generally continued for at least 3–6 months (2, 6). Recanalization rates range from 40% to 75% with early initiation (1, 2, 9). Lifelong AC is indicated for patients with permanent prothrombotic risk factors or recurrent thrombosis (2, 3, 14).

Follow-Up and Surveillance Imaging Monitoring: For patients on AC or observation, cross-sectional imaging (CT or MRI) should be performed every 3 months to evaluate response (3, 9, 11).

Variceal Management: All patients must undergo endoscopic screening. Endoscopic variceal ligation can be performed safely without discontinuing AC (10).

Portal vein recanalization and TIPS

Portal vein recanalization combined with transjugular intrahepatic portosystemic shunt (PVR-TIPS) is an advanced endovascular intervention designed to restore portal flow in patients with chronic obliterative PVT (8, 18). Indications for PVR-TIPS Liver Transplantation Optimization: The primary indication is to convert a non-transplantable patient into a candidate or to facilitate a physiologic end-to-end portal anastomosis during LT, which significantly improves post-transplant survival (9, 11, 18, 19).

Refractory Portal Hypertension: It is indicated for chronic PVT patients with variceal bleeding or refractory ascites/hydrothorax that has failed medical or endoscopic management (4, 8, 10, 15).

Anticoagulation Failure: TIPS is recommended for patients whose PVT progresses despite therapeutic AC (4, 14, 16).

Technical Approach

Access Routes: With regard to the choice of access route, while percutaneous transsplenic access has become the preferred route for recanalizing completely occluded portal veins due to its direct trajectory toward the splenoportal confluence (18), the retrograde transhepatic approach remains a well-established alternative, used either as a primary route or as a salvage strategy when transsplenic access fails (20). Both can be combined in a “through-and-through” fashion to cross challenging occlusions (20).

At present, direct head-to-head comparisons between the transsplenic and transhepatic routes are scarce and limited to small retrospective series, precluding definitive conclusions regarding the superiority of either approach (21). While technical success is high overall, with most PVR-TIPS series achieving success rates between 75% and 100% (15, 22), dedicated cohorts have shown that transsplenic access achieves success rates of 98%–100% (20, 23). Conversely, isolated technical success rates for retrograde transhepatic access have not been specifically reported, as most studies present pooled outcomes (21).

In terms of safety, the largest dedicated comparison found no significant difference in bleeding complications between the transsplenic and transhepatic routes (24). While some systematic reviews have described higher major complication rates associated with percutaneous portal access, these estimates are heavily confounded by the concomitant use of catheter-directed thrombolysis, which is not applicable to the chronic obliterative thrombosis setting (25). Consequently, the choice of access is individualized according to the anatomy and extent of occlusion, splenic vein patency, and operator experience, rather than a demonstrated superiority of one route over the other (19).

Recanalization and Shunting: (I) A hydrophilic wire and angled catheter are used to probe through the fibrotic thrombus to the portal confluence (8, 15, 18).

A GooseNeck snare or balloon is placed in the intrahepatic portal branch to serve as a target for the transjugular TIPS needle (15, 18).

A through-and-through wire is established between the neck and the abdominal access site (18).

A PTFE-covered stent-graft (e.g., Viatorr) is deployed. In LT candidates, the stent is positioned as peripherally as possible to leave a length of native portal vein for surgical anastomosis (8, 15, 18).

Balloon angioplasty (up to 10–12 mm) is performed on the recanalized segment (8, 15, 18).

Embolization: Competing collaterals (e.g., gastric varices) and the abdominal access tract (splenic/hepatic) are embolized using coils or vascular plugs to ensure high flow through the shunt and prevent hemorrhage. In instances where collateral vessels persist following shunt creation, targeted embolization is performed to optimize flow dynamics (8, 15, 18, 26).

Adjunctive variceal obliteration techniques [Balloon-occluded Retrograde Transvenous Obliteration (BRTO) and Balloon-assisted Antegrade Transvenous Obliteration (BATO)]

To illustrate the technical approaches described herein, we present two cases of patients who underwent TIPS for PVT.

Case one

A 31-year-old patient with a history of chronic portal vein thrombosis extending into the superior mesenteric vein presented with cavernous transformation of the portal vein associated with bariatric surgery (gastric sleeve). No other aspects of history could explain the thrombotic event. The patient presented to our service approximately 2 years after initial diagnosis, complicated by the presence of multiple esophageal varices with upper gastrointestinal bleeding that was refractory to optimal medical therapy and endoscopic intervention.

The patient's initial tomography shows portal cavernous transformation associated with splenomegaly, esophageal varices, ascites, and extension of the cavernoma to the superior mesenteric artery. In addition, a complex splenorenal shunt was observed due to multiple collaterals communicating with the left renal vein, with no signs of chronic liver disease on imaging, which was confirmed by liver biopsy (Figure 2).

The case was evaluated by interventional radiology, transplant surgery, hepatobiliary surgery, and hepatology, and it was decided to perform portal recanalization with TIPS.

The patient underwent the proposed procedure, starting with a transsplenic approach to initiate portal reconstruction. After accessing the thrombosed portal vein, angioplasty of the main portal vein was performed. Once the portal vein was open, an angioplasty balloon was positioned within the primary portal vein to serve as a target for subsequent intervention. Access was then gained through the right jugular vein, the right hepatic vein was catheterized, and a transhepatic puncture of the right portal vein was performed to create the TIPS. After TIPS creation, venography was performed, demonstrating persistent hepatofugal flow toward the patient's splenorenal shunt and partial occlusion of the proximal segment of the superior mesenteric vein. Consequently, superior mesenteric vein angioplasty was performed, followed by embolization of the veins draining into the splenorenal shunt using the CATO technique (coil-assisted antegrade venous obliteration). Control venography confirmed conversion from hepatofugal flow to hepatopetal flow and adequate outflow through the TIPS, with a portosystemic gradient of 9 mmHg (Figure 3).

The procedure concluded with the closure of the access sites. The percutaneous transsplenic tract was embolized using coils, followed by manual compression of the transjugular access site.

Case two

A 62-year-old man with alcoholic cirrhosis, Child–Pugh A (six points), and MELD-Na 9 was referred due to chronic portal vein thrombosis extending into the splenic and superior mesenteric veins, and multiple gastric and esophageal varices with portal vein cavernoma, without hepatic encephalopathy (Figure 4).

The patient was experiencing recurrent variceal bleeding despite undergoing outpatient variceal sclerotherapy and secondary prophylaxis with a beta-blocker. Following a multidisciplinary discussion with the hepatology department, it was decided to proceed with reconstruction of the portal vein and splenoportal mesenteric axis, followed by TIPS, to reduce the risk of treatment failure and mortality, particularly because bleeding episodes persisted. In addition, based on gradients and procedural outcomes, the patient was considered a suitable candidate for BATO, BRTO of the varices, or splenic embolization.

Although the patient could have potentially been a transplant candidate, this possibility was remote. Due to the extensive portal thrombosis involving the splenic and mesenteric veins, he would have required a multivisceral transplant, which was not performed at that time at any transplant center in the city.

The patient was evaluated by the interventional radiology department and scheduled for portal vein recanalization + TIPS, with possible BATO or BRTO, depending on the results. Portal and spleno-mesenteric reconstruction was successfully performed via percutaneous splenic and hepatic access, followed by “through-and-through” access, which allowed for the restoration of the venous axis while preserving hepatopetal flow through the TIPS. Final venography demonstrated adequate flow with resolution of esophageal and gastric varices, and a final portosystemic gradient of 10 mmHg (initial: 17 mmHg). The patient experienced no immediate complications (Figure 5). 4. Outcomes and Technical Success Success Rates: Technical success (successful stent placement and flow restoration) is high, ranging from 75% to 100% in expert centers (1, 8, 12, 18, 26), as summarized in Table 1.

Patency: Twelve-month portal vein patency rates range between 78% and 92% (3, 18, 19).

Complications: The most common complication is hepatic encephalopathy, occurring in 18%–41% of patients (1, 3, 4, 8). Other risks include TIPS stenosis (requiring reintervention in ∼30%) and access-related hemorrhage (∼3%–10%) (1, 4, 8, 15, 18).

Clinical Benefits Hemodynamic Decompression: PVR-TIPS achieves a significant reduction in the portosystemic pressure gradient, typically reaching the target of <12 mmHg (15, 16).

Symptom Control: It is superior to standard medical and endoscopic therapy in preventing variceal rebleeding and managing refractory ascites (2, 8, 16).

Improved LT Feasibility: In successful PVR-TIPS cohorts, 90%–100% of transplanted patients have received a physiologic end-to-end portal anastomosis, avoiding the morbidity associated with non-physiologic reconstructions such as cavoportal hemitransposition (8, 12, 15, 18).

Reduced Stasis: The high-velocity flow established by the shunt often eliminates the need for routine postprocedure AC, unless an underlying thrombophilic disorder exists (4, 8, 17, 18, 26).

In conclusion, while the treatment landscape for PVT has improved significantly, the evidence base remains dominated by retrospective single-center series, and prospective randomized controlled trials are still needed to refine the current management approach. Several questions are particularly relevant. First, it remains to be established whether early PVR-TIPS, as compared with anticoagulation alone, improves the rate of physiologic end-to-end portal anastomosis and post-transplant survival in cirrhotic candidates for liver transplantation with chronic obliterative PVT. Second, it remains unclear whether direct oral anticoagulants are non-inferior to vitamin K antagonists or low-molecular-weight heparin in achieving recanalization without increasing major bleeding in patients with Child–Pugh A or B cirrhosis, an issue of growing practical importance given their increasing use. Finally, in patients who achieve successful recanalization after PVR-TIPS, the value of a defined course of postprocedural anticoagulation, as opposed to no anticoagulation, in reducing rethrombosis and shunt dysfunction remains uncertain. Until these questions are addressed, management should remain individualized, prioritizing the restoration of physiologic portal flow and minimizing bleeding risks through multidisciplinary expertise.